Returning values

As well as receiving data, functions can also send back data. To do this, write a dash then a right angle bracket after your function’s parameter list, then tell Swift what kind of data will be returned.

Inside your function, you use the return keyword to send a value back if you have one. Your function then immediately exits, sending back that value – no other code from that function will be run.

We could rewrite our square() function to return a value rather than print it directly:

func square(number: Int) -> Int {
return number * number
}

Now we can grab that return value when the function is run, and print it there:

let result = square(number: 8)
print(result)

If you need to return multiple values, this is a perfect example of when to use tuples.

Become a Swift expert

I wrote a book called Pro Swift that's dedicated to helping you master the Swift language, and it includes seven hours of video demonstrating each technique!